|align="center" valign="top"| {{Icon|file=rota_sludge_well_drilling_icon.png|alt=Percussion - Stone hammer|width=94|link=Percussion - Stone hammer}} <br> [[Percussion - Stone hammer]]
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{|style="height:140px; background:#efefef"
|align="center" valign="top"| {{Icon|file=rota_sludge_well_drilling_icon.png|alt=Sludging - Asian sludge hammer|width=94|link=Sludging - Asian sludge}} <br> [[Sludging - Asian sludge]]